Intensity controlling system for receivers



Nov. 8, 1932; o. PAINTER INTENSITY CONTROLLING SYSTEM FOR RECEIVERS Filed July 26, 1930 Patttttd Novas, 1932 UNITED STA S I mumcn'o. 24mm or art. Pawn, 'mmsom', Assmuon 'ro PROGRAM smvrca PATENT OFFICE COMPANY, 01 8'1. PAUL, MINNESOTA, A CORPOBATION OF DELAWARE CONTROLLING SYSTEM FOR RECEIVERS -Application flled l'uly 26, 1980. Serial H0. 110,828. I

My present invention relates to intensity control systems for loud speaking telephones and other receivers and more particularly to a system for controllingthe potential and/or current impressed'ulpon a receiver such as a. loud speaklng telep one or televisor,

, manipulation of any onev of several independently operable controlelements.

- It is an object of my invention to provide an intensity controlling system for receivers, such as loud speaking telephones wherein the potentials impressed upon and/ or the current. delivered to receivers suchas loud speaking telephones may be adjusted and controlled by either of two physically separated elec trical intensity controlling devices, such aspotentiometers. q

Such a system is especially well adapted fordual volume controls in connection with a radio set. The loud. speaker may be positioned in a convenient locationwhere it can he heard from several rooms and-with my system the volume may be controlled by independent manipulation of devices located in various portions-of a house or building.

It is a further object of my invention to provide an intensity control system of the type described wherein two independently operable volume control devices are provided, located, if desired.'at diiferent points remote from an electrical receivingdevice, such as a loud speaking telephone and so connected with said receiver and a source of, electrical. energy such. as a source of soundcarrying current that the intensity or volume produced .by the; receiver may be controlled "within the range available bythe manipulation .of either oneof said intensity controlling devices without. requiring any manipulation of the other controlling'devlce \and wherein the intensity or volume" may be reduced to zero by independentmanipulation of either of said controlling'd'evices without opening any of the circuits involved in the system orinthe power supply source serving t e system,

from the following-description made in conmotion with, the accompanying drawing by the ume control devices P and 1?.

These and otherobjects will be a:pparent A schematic electrical diagram of a system embodying my-invention'is shown for use in controlling the volume of sound produced by a loud speaking telephone. It will, of course, be understood that my system is equally applicableto dual control systems for regulating, from twophysicall separated. points, the potential or current e ectin electrically operated receivers or devices 0 various classes.

In the embodiment of the invention illustrated,- a source of sound-carrying current,

such as an audio-frequency amplifier T is connected with a loud speaking telephone S.

Two similar intensity or volume control devices P and P are provided which may be conventional potentlometers, and through which a portion of the sound-carryin current or audio-frequency energy availa 1e at the output terminals T and T of amplifier T is delivered to the loud speaker S.

1 The output terminal T of the amplifier T of equal resistances or impedances having uniform distribution of resistance or impedance between their respective terminals. This condition, however, is not essential to the successful functioning of my device. As shown, resistance element R has its ends or terminals connected to terminals A and B respectively, while resistance element R has its ends connected toterminals A and B respectively. The volume control devices are also provided with movable elements or contacts M and M respectively and obviously said movable elements maybe adjusted to .make contact with any desired vpoints on their respective resistance or impedance elements R? and R Movable element M is connected with a terminal C which is connected by means of conductor X with terminal S of the loud speaking telephone S.

Element M is connected with the terminal C which is connected with terminal S of the loud s eaking telephone by means of a conductor a The audio frequency potential existing.

between the terminals T and T of the audio frequency amplifier T also exists between the terminals A, and B ot volume control device P and between the terminals A and B? of volume control device P due to the connections previously described. 7 I

Assuming that the resistances or impedances of the two elements R and ZR are equal and that the distribution of resistance or impedance between points A and B and between points A and B is similar, it then follows that no potential exists between cor- Wllllth the same assumptions, it follows that Y t e otential' existin between non-correspon ing points of said elements R and R is substantially proportional to the distance between the point selected on one resistance or impedance element and the oint on that same resistance or impedance e emen-t which corresponds with the point engaged by the movable contact on the other resistance or impedance element. The same results can be obtained of course if resistance elements 11. and R are of unequal resistances and'even though the resistance throughout the lengths of the respective elements is not distributed uniformly;

Since t e movable elements M. and M of the volume control devices P" and P can be brought into contact with any desired points on the resistance or impedance elements R devices P and P itis apparent that various portions of the audio frequency potential available at the terminals T and T! of the audio frequency amplifier A can be caused to exist between the movable elements M and M of the volume control devices and "that the potential existing between the said movable elements is transmitted to the terminals Sjand S of thejloud speakin telephone S. It is then apparent that a c ange in the position of the movable element of either one of the volume control devices will result in a change in the audio frequency potential impressed on the coil of the loud speaking telephone S and will therefore cause a change/in the volume or intensity of sound produced by the said loud speaking telephone.

It will also be apparent that when the mov-- able elements M and M of the volume con trol devices are positioned similarl with respect to impedance elements R and 2 that zero potential will be impressed upon the loud televisors and other electrically 0 rated speaker S and no sound 'will be produced. With my device therefore either one of the volume or intensity controlling devices may be manipulated inde dently to a position where it will be matc ed to shut off the loudspeaker and cause zero potential to be imp' thereon.

From the foregoingdescription it will be seen that I have invented an extremely simple but highly eflicient system for conveniently controlling the'intensity of loud speakers,

receivers. It willfurther be seen at the invention is equally applicable to control currents delivered to electrical receivers and it is expressl understood that I do not limit myself to t e particular use of my system or to the embodiment for volume control illustrated in the drawing. 1

-It will,.of course, be understood that various changes may be made in the form, details," pro rtions and arrangement of the parts, wit out departing from the scope of applicants inventlon, which, generally state consists in a device capablejof carrying out the objects above set forth, and in the novel parts and combinations of parts disclosed and defined in the appendedclaims.

What is claimed is:

1. In an intensity controlling systom'for with the particular position ofthe other volume control device receivers such as loud speaking telephones or 7 and B respectively of the volume control of current and the other mull of of a point remote from said first mentioned po-'- tentiometer, electrical connections between said source of current and said potentiometer:

for impressing upon each of said potentiometers a potential, and electrical conpections between said receiver and said otentiometers whereby potei'itial impressed upon said receiver may be varied by ulation of either of sai otentiometers.

independent manip- .s

3. In an intensity controlling system for i is loud H telephones or televisors, a source of sound or ima carrying current, a air of electrical con nctors connected to sai source, an independently controllable potentiometer, a second independently controllable potentiometer located at a point remote from the first mentioned potentiometer, each potentiometer comprismg a resistance element and a contact element adjustably engaged with said resistance element, the ends of each resistance element being connected respectively to the conductors of said air, and a receiver, the two terminals of sai receiver being respectively connected to the contact elements of the two 15 otentiometers.

In testimony whereof I afiix m ature.

LAURENCE O. P R. 

